Art of the condensation of gases or vapors into their liquid forms.



P. P. PETERSON.

ART OF THE GONDENSATION OP GASES 0R VAPORS INTO THEIR LIQUID FORMS.APP'LIOATION FILED JULYfi, 191 1.

1,031,664. I Patented July 2, 1912.

qwme/am UNITED STATES PATENT fonrion.

FRANKLIN r. rn'rnnson, or enov'n o1rY ,'PENns Lv'ANI A, AssIqNoa, BYmnsnn ASSIGNMENTS, TOTHEYAMERICAN-GASOL con/manner PITTSBURGH, PENNSYL-VANIA, A CORPORATION or wear vmemm.

ART OF THE (ION,DEN'SA'JIIOIII'. OF GASES 0R, VAPORS INTO THEIR-LIQUIDFORMS.

Specification of Letters Patent. Application filed .luly '5, 1911.Serial-K056536362.

Patented July 2, 1912.

My present invention relates to the process for the separation of theseveral families of a series of condensable gases or vapors,

' suchas the families or compounds of hydro carbon gases which flow frompetroleum oil or gas wells, intotheir respecti've'fractions,

as described in refinery distillation processes, having more or lessconstant boiling points and compound structures.

In the process at present employed and known, for the most part,aslmethodsfor extraction of gasolene from natural gas, it has developedthat when high pressures are used in the condensers that are-employed,certain of the low boiling point fractions in the compound gases treatedare condensed and held in mechanical combination with the higherspecific gravity, higher boiling point liquids which are sought. This result is undesirable from a view point of producing and marketing theheavier liquids. The very volatile lighter fractions held in combinationwith the heavier product has a tendency when confined in a retainer tocreate undesirable pressure on any slight increases of temperature. Ithasa tendency to create ebullition strong enough 'to throw a portion ofthe contents out of a vessel if the same be suddenly opened and thevapor pressure released. It is, furthermore, desirable to separate formore valuable uses these fractions which .can be readily liquefied andwhich have such low boiling points as to be volatile at all ordinarytemperatures.

Referring to the accompanying drawing: Figure 1 is a general arrangementplan View of a condensing plant arranged to separate the condensateobtainable into fractions or stages. Fig. 2 shows a side elevation of aportion of the condensing equipment, composed of cast iron, verticallydisposed manifolds or headers, 37, and cooling pipes, 6, communieatingbetween the headers. Fig. 3 is a horizontal sectional view of a form ofcooler designed to utilize the heat reaction of the rapidly expandingresidue gas. as a cooling medium to extract heat from the gas undertreatment for separation of'condens-" able vapors. The part this detailplays in the operation will be described further on. Fig. 4 is a sideelevation of details 21, 23, 24, 25 and '36 plan and shows detail 24partially in section.

It 'is obvlous that various differing details of construction and ofcooling contrivances might be employed to the end that I seek but, forconvenience of illustration, I

have selected the combination of details which have been found effectualin performing cooling and condensing functions in various arts involvingsuch treatment of gases and, in'particular, the art of condensing theheavier portions of natural gasfrom oilbearing strata into liquids.

I will describe the process referring to the drawing as follows: 1 is acompressor andthis detail undertakes to compress the gas medium beingtreated through the -first stage of compression. The gas is taken intothe compressor cylinder through pipe 4 and discharged through pipe 5into the header 37 (shown in elevation in detail in Fig. 2), from whenceit is distributed in several streams through cooling pipes 6, whereinthe temperature may be controlled to any desired degree within thoseranges involved by the climatic state and the nature of thecompressor-andv extent of first stage compression. The temperature maybe con-.

trolled by the use of water flowing over the pipes or by the free orrestricted circulation of air. The gas, on leaving the collectingheader, 37, enters the: traps 7, where any liquid present is separatedand drawn off into tank 32. -Leaving the trap through.

pipe 8, the gas passes further through the expansion cooling coil 9.From the detail section shown 1n Fig. 3 we can follow the path of thegas under compression through the internal pipe 8 the length of the pipeand return through the double wall return I bend 40, delivering into thetank'10.- The trap '7 and the tank 10 serveto separate the accumulatedliquid condensed in the first stage of compression, from whence it-isdelivered into the stock tank 32. From the tank 10 the gas is deliveredto the intake of the second stage compressor 2, and

through the compressor and the connecting pipe 12 into the secondstagecondensing coil 13, the trap 14, the expansion cooling coil 17 theaccumulator tank 16, and into the third stage compressor 3'. In this sec0nd stage the same method of separation of liquid is followed as inthe'firststage, the condensate being gathered and stored in tank 34. Thegas is then made to pass through the third stage, or as many stages ofcompression as may be desired for as many separations or fractions ofcondensation as are required and the condensates may be revaporized andpassed through the process as many times as may be necessary forobtaining any desired constancy of b011- ing point.

After the'last compression the gas passes by the pipe 18*t'o the coolingcoil 20, thence by the pipe 22, trap 2l-through the cooling coil or'loop23. From the loop 23 the gas passes to a tubular condenser 24 shownpartly in section in Fig. 4. This condenser is of ordinary form havingheaders near the ends connected by tubes. The gas enters from the loop23 to one of the end spaces,

passes through the tubes to the op osite end I and the condensates aredelivered y way of the pipe 35 to the storage tank 36. The gaspassesthrough the tubes of the chamber 24 and into the final accumulator tank'25.

From tank 25, the gas, now considered resi due, is released, preferablyintermittently. through some form of pop or spring relief valve, and.discharged into the chamber 24, as above stated ,atthe point'26. -Therapidly expanding gases from ahigh pressure to a low-pressure and from asmaller to a greater volume produce an endo-thermic or heat' absorbingreaction and the final re-absorption of heat into the expanding residuegas is carried as far as may be found efiicient by means of theexpansion cooling coils 23, 17, 9, etc. These coils, shown in detailinFig. 3, make this part of the treatment quite clear. The expanding gas,now .very much reduced-in pressure, after leaving 24, by

means of ipe 27 is made to enter the outer casings o the expansion coils23 which are similar .in construction to the expansion coils, 9, shownin the sectional detail in Fig. 3 and pass in series from one coil toanother of the different stages around the column of gas under pressurein the inner pipes and in the opposite direction to the travel of thecondensing gas.

The separation of condensate from the final stage is effected by meansof drainage connections from the trap 21, the expansion chamber 24 andthe final accumulator tank 25 by a tank 35 into the final storage tank36. In conducting these stage operations, such pressures andtemperatures may be produced and maintained in the several separatestages as conform to the critical temperatures and pressures of thedifl'erent compounds or' fractions present in the complex gas and whichare desired to be so arated' out more or less perfectly into dierent'portions or fractions having more nearly unity of composition.

' I :have found in separating the different compounds from natural gasthat good results areobtained by compressingthe gas at the first stageto a pressure of 50 lbs. per sq. in. and reducing the temperaturethereof to' 60 F. degrees, and by compressing the sec- 0nd stage to 300lbs. sq. in. pressure and reducing the temperature to 40 F. degrees, andincreasing the pressure at the third stage'to 650 lbs. per sq. in.andreducing the temperatureto 32 F. degrees. It will be understood thatthese pressures and temperatures must be varied with reference to thegases being operated upon and the desired pressures and temperatureswhich consists in compressing and cooling the gas and collecting theliquid condensed and then compressing -and cooling. the gas residue andcollectingthe liquid from the residue.

2. The art or process of condensing and separating differing compoundsin natural 'gas in which there are different .critical pressures andtemperatures which consists 1n compressing the gas in a plurality ofstages, cooling the same at each stage and collecting the condensate foreach stage separately.

3. The art or process of condensing and separating difi'ermg compoundsin natural gas in which there are different critical pressures andtemperatures which consists in compressing the gas in a plurality ofstages and increasing the-pressure at each stage, cooling the gas ateach stage and 001- lecting the condensate for each stage sepaf rately.

4. The art or process of condensing and separating difi'erent compoundsin natural gas in which there are diflerent' critical pressuresandtemperatures which consists .in compressing the gas in a plurality ofstages, and increasing the pressure with each stage and decreasing thetemperature with each stage and collecting the condensate for each stageseparately.

5. The artuor prccess of condens'ng and flow in'ceuntercurrent to andinheat inter- 10 separating difiering comp unds in natural changingrelation with the compressed gases. .gas in which there are difierentcritical In testirnony whereof I have hereuntc set pressures and temeratures which consists m hand 1n the presencecf two SUbSCI'lblIlg incompressing an cooling the gasand colwltnesses.

lectingthe liquid condens d and then c m- FRANKLIN P. PETERSON. pressingand cooling theTgas \residue and Witnesses: 1 collecting the liquid fromthe residue, and WM. J SLOAN,

causing the expanded residue bf the gases to BESS R. "S. McMULLEnQ

